How Much Calcium Is In Broccoli? | A Numbers Breakdown

You’ve probably seen broccoli on lists of calcium-rich vegetables right alongside kale and bok choy. But when you actually check the numbers, the amounts vary wildly — 25 mg here, 112 mg there, 180 mg in another source. That kind of spread makes it hard to know what to trust, especially if you’re relying on broccoli to meet your daily calcium needs.

The honest answer is that broccoli does contain calcium, and it delivers that calcium in a way your body can use efficiently. But the exact amount depends on whether you’re eating it raw, boiled, or frozen, and which expert source you consult. This article breaks down the numbers so you know what one serving actually provides.

Where The Numbers Come From

Different health organizations measure broccoli calcium content under different conditions, which explains the wide range. UCSF Health reports 180 mg per cup of cooked broccoli — one of the higher estimates from a major medical institution. The Bone Health & Osteoporosis Foundation lists the same serving at 60 mg, a third of that figure.

The USDA National Nutrient Database sits closer to the lower end, reporting 61 mg per cup of frozen, cooked broccoli as the standard value for that form. The International Osteoporosis Foundation records 112 mg of calcium per 120 g serving of raw broccoli. None of these sources are wrong; they’re just measuring different forms.

Why The Same Vegetable Gives Different Numbers

Cooking method matters. Boiling leaches some calcium into the water, which you’d lose if you drain the broccoli. Freezing and then cooking also shifts the final mineral content. And raw broccoli has a different water-to-solid ratio than cooked, so a cup of raw florets weighs less and contains less calcium by volume than a cup of cooked florets.

Why The Calcium Quality Matters More Than The Quantity

Total milligrams only tell part of the story. What matters more is how much of that calcium your body can actually absorb. Many vegetables contain oxalates, compounds that bind to calcium and prevent your gut from absorbing it. Spinach is famously high in oxalates, which is why its high calcium content of about 240 mg per cup cooked is largely unavailable to your body.

Broccoli is different. It’s naturally low in oxalates, which means the calcium it contains stays bioavailable. Research has measured broccoli’s calcium absorption rate at roughly 41%, placing it among the most efficient vegetable sources for this mineral. The same literature notes that food matrices play a significant role — the way calcium is packaged inside the vegetable determines how much you actually get.

• Oxalates matter: Foods high in oxalates, like spinach and Swiss chard, bind calcium in the digestive tract and reduce absorption significantly.
• Broccoli is low-oxalate: Its naturally low oxalate content preserves calcium bioavailability, making it more efficient than many leafy greens.
• Absorption rate: Broccoli’s calcium absorption rate of roughly 41% is among the highest for any vegetable source.
• Kale comparison: Kale and broccoli are both low in oxalates, making them strong choices for non-dairy calcium.
• Serving size matters: The calcium numbers change considerably between raw, boiled, and frozen preparations.

The practical takeaway is simple: a vegetable doesn’t need to have the highest total calcium count to be useful for bone health. A lower amount your body can actually absorb beats a higher amount that passes through largely unabsorbed.

Calcium In Broccoli Compared To Other Foods

Seeing how broccoli stacks up against other common calcium sources makes the numbers easier to evaluate. The following table compares broccoli in its various forms to other foods, using figures from major osteoporosis foundations and the USDA.

Per the USDA broccoli calcium fact sheet, these values reflect standard serving sizes used in clinical nutrition guidance.

Food	Serving Size	Calcium (mg)
Cooked broccoli (UCSF)	1 cup	180
Raw broccoli (IOF)	120 g	112
Cooked broccoli (BHOF)	1 cup	60
Boiled broccoli (ROS)	3 tbsp (80 g)	25
Frozen cooked broccoli (USDA)	1 cup	61
Whole milk	1 cup	300
Cooked kale	1 cup	90

Broccoli sits in the middle range for vegetable calcium sources. It’s not as concentrated as dairy, but the roughly 41% absorption rate means a cup of cooked broccoli delivers somewhere between 24 and 74 mg of usable calcium depending on which source number you start with.

How To Maximize Calcium From Broccoli

Getting the most calcium from broccoli comes down to two things: how you prepare it and what you eat alongside it. Small adjustments can make a meaningful difference in how much calcium ends up in your bloodstream rather than going down the drain.

1. Steam instead of boil: Boiling leaches calcium into the water you pour away. Steaming keeps more of the mineral in the vegetable itself.
2. Eat with vitamin C: A squeeze of lemon juice or a side of bell peppers may help your gut take up more calcium from the meal.
3. Avoid high-oxalate pairings: Combining broccoli with spinach or Swiss chard in the same meal introduces oxalates that can bind calcium from both foods.
4. Include a little fat: Calcium absorption benefits from some dietary fat. A drizzle of olive oil or a small amount of cheese helps your body process the mineral.
5. Use the cooking water: If you do boil, save the water for soups or sauces so the leached calcium stays in your meal.

These tweaks are small but cumulative. If you eat broccoli several times a week, each adjustment pushes a bit more calcium into your system. Over months, that difference adds up.

What The Research Actually Shows About Broccoli Calcium

The strongest evidence for broccoli as a calcium source comes from bioavailability studies. A 2024 study in Food Research International found that the bioaccessibility of calcium from broccoli was the highest among tested vegetables, surpassing even skimmed milk. Bioaccessibility refers to the amount of a nutrient released from the food matrix and available for absorption in the gut.

A 2015 review in the British Journal of Nutrition, published through NIH, measured broccoli’s calcium absorption rate at 40.9% and attributed it to the vegetable’s low oxalate content. The same review explains that oxalates bind to calcium in the digestive tract and reduce the amount your body can use. Because broccoli keeps oxalates low, its calcium stays bioavailable through digestion.

A 2021 review in Nutrients adds context by noting that calcium absorption from food products ranges from less than 10% to more than 50%, with the food matrix playing a significant role. Broccoli lands near the top end of that range. Research suggests that adding just 0.1 g of oxalate to a food measurably reduces calcium absorption — another reason broccoli’s low-oxalate profile matters.

How Broccoli Compares To Other Low-Oxalate Vegetables

Vegetable	Oxalate Level	Calcium Absorption
Broccoli	Low	~41%
Kale	Low	~40% (estimated)
Bok choy	Low	~40% (estimated)
Spinach	High	~5%
Swiss chard	High	~5%

These absorption differences are dramatic. A cup of spinach has 240 mg of calcium on paper, but at roughly 5% absorption you get about 12 mg of usable calcium. A cup of cooked broccoli with 60 mg of calcium and 41% absorption gives you about 24 mg — double the usable calcium from a quarter of the total.

The Bottom Line

Broccoli won’t replace dairy as your primary calcium source, but it’s a surprisingly efficient one. Depending on preparation, a serving delivers anywhere from 25 to 180 mg of calcium, and the low oxalate content means roughly 41% of that amount is actually absorbed. You’d need about 1.5 to 4 cups of cooked broccoli to match the absorbable calcium in a glass of milk, depending on the source numbers you use.

If you’re tracking calcium for bone health, check the preparation method on your broccoli and aim for steamed or lightly cooked rather than boiled and drained. Your primary care doctor or a registered dietitian can fit broccoli into your overall calcium target based on your specific needs and other dietary sources.